The first carpo-metacarpal (i.e., 1CMC) joint, found at the base of the thumb, is complicated in that it does not have a single axis of rotation. Rather, the first metacarpal sits on the trapezium in a saddle-shaped geometry. This allows each of the bones in the first carpo-metacarpal joint to rotate about each other around axes of rotation oriented transversely to one another.
The 1CMC joint has a propensity to wear out and develop arthritis, causing pain at the base of the thumb and resulting in weakness of the gripping and pinching abilities of the hand. In patients with osteoarthritis, this condition is referred to as basal joint arthritis of the thumb. Conservative and medical treatments of the condition, including splints, NSAIDs and cortisone, are commonly used but are not always effective, leading to consideration of surgical solutions.
One surgical approach involves the removal of the trapezium, linking the first and second metacarpals at their bases with tendon graft and inserting a pad made of tendon graft or artificial material to cushion the space left by the now absent trapezium.
Other surgical approaches include the use of a prosthetic device to substitute one half or all of the 1CMC joint. Examples of these are described in U.S. Pat. No. 5,645,605 to Klawitter, International Publication WO2010/033691 also to Klawitter, U.S. Pat. No. 7,182,787 to Hassler and U.S. Pat. No. 7,641,696 to Ogilvie.
It has been observed that known surgical techniques and devices to treat the arthritic 1CMC joint achieve one or more of early reestablishment of adequate range of motion, reduction or elimination of pain, recovery of strength and stabilization of the joint, but none achieves all of them to a satisfactory degree.
Additionally, accurate means for performing a wedge osteotomy in small bones, a particularly useful arthroplastic procedure for restoring pain free stability to a patient with basal joint arthritis of the thumb, are not currently available. Furthermore, a prosthetic device that can be used to emulate the result of a wedge osteotomy is currently unavailable for those cases when replacement of a damaged articular surface is indicated.
What is needed is a system, apparatus and methods that provide a surgeon with surgical options and the corresponding devices to treat a diseased joint and to overcome the limitations of the heretofore-known devices.